1. Field of the Invention
The present invention relates to a method for quantitatively assessing the degree of deformation undergone by a surface profile of a wafer following the formation of conformal surface layers by means of epitaxial growth, oxidation and/or deposition, during the manufacture of semiconductor devices.
2. Description of the Prior Art
Planar technology is used in the manufacture of semiconductor devices and integrated circuits. It comprises diffusing, in clearly defined areas, the doping agents necessary for the production of the semiconductor junctions. This type of technology requires a succession of photolithographic procedures and perfect alignment of each individual mask relative to the preceding one. In critical working stages, slight inaccuracies, often of cumulative nature, can cause serious production delays in so far as the automatic alignment performed by the production apparatuses with successive masks is compromised. Often, accurate assessment of these problems may not be achieved during the phases of design and manufacture of prototypes, and may instead become apparent on the start-up of mass production, requiring manual intervention for the purposes of alignment whenever the automatic alignment system signals an error status. Means and procedures for studying geometric distortion are somewhat complicated and require a considerable expenditure of time.